In the Philippine criminal justice system, the imposition of penalties is governed by the principle of proportionality and humanity. While the law seeks to punish every transgression, it also recognizes that the literal, successive service of numerous sentences could result in a term of imprisonment that exceeds a natural human lifespan.

To address this, Article 70 of the Revised Penal Code (RPC) establishes the Three-Fold Rule.

I. Legal Basis and Definition

The Three-Fold Rule is a mandate for the simultaneous or successive service of sentences when a culprit is convicted of multiple offenses. It acts as a legal ceiling on the total duration of imprisonment.

Article 70, RPC: "Notwithstanding the provisions of the next preceding article, the maximum duration of the convict's sentence shall not be more than three-fold the length of time corresponding to the most severe of the penalties imposed upon him."

The Absolute Ceiling

Regardless of the "three-fold" calculation, the law provides an absolute cap: The maximum period of imprisonment shall not exceed forty (40) years.

II. Conditions for Application

The Three-Fold Rule does not apply automatically to every person facing multiple charges. Specific conditions must be met:

Multiple Convictions: The accused must have been convicted of several offenses.
Successive Service: The nature of the penalties must be such that they can be served one after the other (usually involving deprivation of liberty like Prision Mayor or Reclusion Temporal).
Maximum Limit Reached: The sum of all individual penalties must exceed three times the most severe penalty, or exceed 40 years.

III. Mechanics of Calculation

To apply the rule, the court follows a specific hierarchy of operations:

1. Identify the Most Severe Penalty

Among all the crimes for which the accused was convicted, the court identifies the one with the longest duration.

2. Triple the Most Severe Penalty

Multiply the duration of that "most severe" penalty by three. This becomes the provisional limit.

3. Compare with the 40-Year Cap

The convict will serve whichever is lesser between the "three-fold" duration and the 40-year absolute limit.

Example Scenario:

Suppose an individual is convicted of five counts of Robbery.

Crime 1: 10 years (Most Severe)
Crime 2: 8 years
Crime 3: 8 years
Crime 4: 8 years
Crime 5: 8 years
Total Sum: 42 years.

Application:

Three-fold the most severe: .
Absolute cap: 40 years.
Result: The convict will serve only 30 years, as it is the lower limit.

IV. The Rule on "Complex Crimes" vs. "Multiple Crimes"

It is vital to distinguish the Three-Fold Rule from Article 48 (Complex Crimes).

Complex Crimes: Occur when a single act constitutes two or more grave or less grave felonies, or when an offense is a necessary means for committing the other. Here, only one penalty (the most serious in its maximum period) is imposed.
Multiple Crimes (Three-Fold Rule): Applies when there are separate acts resulting in separate crimes. Each crime carries its own penalty, which are then aggregated and subjected to the Three-Fold Rule.

V. Key Jurisprudence and Limitations

The Supreme Court has clarified several nuances regarding this rule:

Not a Limitation on Sentence Imposition: Judges must still impose the specific penalty for each crime in the judgment. The Three-Fold Rule is applied during the execution of the sentence, not as a way to lower the penalty in the decision itself.
Subsidiary Imprisonment: If the convict has no property to pay fines, they may undergo subsidiary imprisonment. However, this cannot be imposed if the main penalty is higher than Prision Correccional, and it cannot make the total term exceed the limits set by the Three-Fold Rule.
Succession of Sentences: Sentences are served in the order of their severity, starting with the most severe.

VI. Rationale: The Humanized Penal System

The philosophy behind Article 70 is rooted in the correctional and rehabilitative nature of Philippine law. By capping the sentence at 40 years or three times the most severe charge, the state avoids "inhuman" punishment while ensuring the convict still serves a significant period of incarceration that reflects the gravity of multiple offenses.